| Summary: | 碩士 === 輔仁大學 === 食品營養學系 === 82 === A mixed gel consisted of gelatinized corn starch (GCS) and
alkali-treated glutens (ATG) with different hydrophilicity was
used as a model system to investigate effects of protein hydro-
philicity and storage temperatures on the gel structure when
ana- lyzed by using a rheometry and a differential scanning
calorimet ry.Further studies were proposed tounderstand how the
physico-che micalchanges in foods could be related to the
contents of amylos e/amylopectin and the protein hydrophilicity
in the mixed gels during storage.both hardness andmodulus of
elasticity of the ATG/ GCS mixed gels decreased as anincrease
of ATG hydrophilicity.This maybe associated with
highercompatibility of GCS to ATGs of low h ydrophilicity than
those ofhigh hydrophilicity. Moreover, the har dness and the
modulus ofelasticity ofthe mixed gels were quadrati cally
related to thetemperature,and reached a maximum value at 3. 5℃.
A distinct endo-thermic peak,indicatinga meltingofthe recryst
allized amylopectin,was observed between 55and 85℃.The melting
e nthalpy decreasedwith a decrease in hydrophilicity of ATGs
when t he mixed gelwas stored at temperatures below 10℃.The
realignment ofamylo-pectin or an increase of entropy under
elevated temperatu res.The effects of amylopectin content and
storage time on the mo le-cular structure of mixed gelwere
conducted by examining thecha nges of their rheometrical and
thermal properties.Two kinds ofmix ed gels,a low hydrophilic
25℃ATG/GCS and a high hydrophilic60℃A TG/GCS were used. This
confirmed our hypothesis that ATGs of low hydro-philicityw ere
more compatible with amylopectin,presumably bothmolecules mig
ht exist in forms of an entanglement or a intermo-lecular
interac tion.The mixed gel of 25℃ ATG/GCS showed a highergel
strength an d a lower recrystallization enthalpy than that of60
℃ ATG/GCS,ind icating that the low hydrophilic ATG was more co-
mpatible to star ch than the high hydrophilic 60℃ATG.
|
|---|
